The invention relates to a mask management method and bar code reading apparatus thereof, and in particular to a bar code reading apparatus for managing mask bar codes.
FIG. 1 is flowchart of a conventional mask management method. A mask and a mask protective case are provided (step S11). The mask is contained in the mask protective case. As shown in FIGS. 3a and 3b, the mask 100 in the mask protective case 200 has mask bar codes 110 and 120 thereon. The mask protective case 200 is a transparent box with red, blue or colorless colors according to different brands, materials, and transmittance. The conventional mask management method requires a list of mask bar codes provided by suppliers. Then box bar codes are printed (step S12) according to the list. An exposure equipment requires to use a standard-sized mask pod for automatic exposure process. In a clean room, a mask 100 is taken out of the mask protective case 200 and disposed into a mask pod (step S13). And then, a box bar code is stick on the mask pod (step S14) to indicate different mask information thereon. During exposure, the mask pod is disposed in an exposure equipment (step S15), and the exposure equipment automatically scans the box bar code and inputs the scanned information step S16. And then the exposure equipment utilizes the mask for exposure process (step S17).
Another mask management method is shown in FIG. 2, in which a step of sticking the box bar code on the mask pod is omitted. After a supplier provides a mask and a mask protective case (step S21), the mask protective case is changed to a mask pod (step S22) such that the mask is moved from the mask protective case to the mask pod. The mask pod and the mask therein are disposed in the exposure equipment (step S23). After automatic scanning the mask bar code and inputting scanned information (step S24), the exposure equipment starts exposure process (step S25).
According to the mask management method in FIG. 1, since the box bar code is produced from a list of information from suppliers, mistakes due to human-errors sometimes occur. For example, the list of mask information from the supplier does not correspond to the masks in the mask protective case. In addition, during box bar code manufacturing process, mistakes can cause inconformity between the box bar codes and the mask bar codes. Moreover, the mask management mask in FIG. 2 omits the step of sticking the box bar does. It is difficult for mask management since some masks could be mistakenly put in the mask protective case during mask moving process. Also, during exposing process, subsequent procedure management can be interrupted and equipment could be crashed because of using wrong masks, wasting lots of money and time.
Furthermore, most of current exposure equipment only reads one-dimensional bar codes. Thus, if the bar code is two-dimensional, the exposure equipment cannot recognize two-dimensional bar codes, and unable to input the masks, interfering production process. In addition, if the step of matching the box bar codes with the mask bar codes is omitted, serious manufacturing and material losses can be resulted because of using a wrong mask.
Thus, the conventional mask management methods still cost significantly with limited bar code reading ability, as yet the conventional method still cannot accurately provide correct mask for exposure process.